Toshiba TC9349AFG Manual page 33

Constant-voltage circuit (V
There is a built-in constant-voltage circuit (V
converter for the VT and for the CPU and A/D converter. The constant-voltage circuit utilizes the doubler V
supply for the CPU and outputs a constant voltage of 1.5 V from the V
data port for rectifying the constant-voltage value V
programming as correction data is usually determined at the time of shipment.
Y1 Y2 Y4
φL16(E)
TR0
TR1 TR2
The constant-voltage rectify data
Note: After system reset, this serves as the port for data rectification so that V
shipment. For this reason, do not access this port.
Note: During reset or a clock stop, the V
LCD driver doubler circuit (V
There is a built-in doubler circuit for LCD drivers (V
The doubler circuit for LCD drivers outputs a 3 V constant voltage doubled from a 1.5 V constant voltage through the
capacitor-utilizing charge pump system doubler.
1.5 V constant-
voltage circuit
V EE
9
0.47 µF
Note: During reset or a clock stop, the V
Note: The V doubler potential is used for the power supply in the I/O port, etc.
LCD
Note: The doubler clock can use 37.5 kHz or 75 kHz (OSC2 bit).
)
EE
) to provide the reference voltage of the LCD driver and DC/DC
EE
, and voltage can be rectified per 20 mV. Do not set this port through
EE
Y8
TR3
pin becomes high impedance.
EE
)
LCD
) that acts as an LCD driver power supply.
LCD
37.5kHz
or
75kHz
Doubler circuit
C3
6
0.1 µF
pin outputs the V
LCD
33
pin. There is a constant-voltage compensation
EE
is set to 1.5 V at the time of
EE
C4 V LCD
8
7
level.
CPU
TC9349AFG
pin power
DB
To LCD driver
0.1 µF
2006-02-24